2.7 Accuracy In Design And Manufacture

Question 1

Marking Devices

Answer 1

• Engineer blue to make scribed lines clear
• Scribe for metal
• Beam compasses for large radii
• Laser devices such as a cross line laser level
• Surface plates and marking gauges

Question 2

What is a dial test gauge

Answer 2

Single axis measuring device used to measure a bearing giving potential for providing direct input to computer systems

Question 3

Jigs

Answer 3

Devices used to control the motion of a tool relative to the workpiece
Card for small scale, metal for larger scale as lasts longer.
Good for repetition and accuracy

Question 4

Fixtures

Answer 4

Robust frames with holding points and clamps that are used to hold work pieces firmly in place. Every component is held in the same position to ensure consistency

Question 5

Templates

Answer 5

Rigid shape or pattern often made of manufactured board or sheet metal used to transfer a design onto a workpiece

Question 6

High precision working

Answer 6

Micrometers, vernier callipers and coordinate measuring machines

Question 7

Impact of CNC

Answer 7

Processes don’t require marking due to codes generating by cam/cad. Ensuring optimum layout is necessary to avoid waste of materials.

Question 8

Importance of accuracy

Answer 8

Save time
Parts fit and function properly
The designer must consider what an acceptable range of accuracy (tolerance)

Question 9

Examples of situations where there is a need for accuracy

Answer 9

Cutting the gears for a watch movement
Ensuring that threads for nuts and bolts fit correctly
Fitting a new glazing unit in a window frame
Positioning for knock down fitting a in self-assembly furniture

Question 10

What factors affect tolerance

Answer 10

Material, size, function and need for interchangeability